The Study Of Shear Behavior And Bearing Capacity Calculation Method For Cold-formed Steel Framing Shear Walls With Large Opening

Recently, a series of studies was carried out for cold-formed steel framing at homeand abroad. There are many achievements but lack of research for shear behavior andbearing capacity calculation method of cold-formed steel framing shear walls with largeopenings (width>400mm, height>600mm). Its theoretical design basis is not perfect;In addition, the most of domestic and foreign research discuss shear resistance ofcombined wall with no vertical load exclusively, but in fact, the column in wall alsoneed to withstand vertical load, and it is obviously unreasonable to assess shearresistance of combined wall regardless of vertical load. In this paper, combining withthe existing test results, researching the theoretical analysis for shear behavior andbearing capacity for cold-formed steel framing shear walls with large openings. Mainlycompleted the following work:①Based on existing test results, research the large opening cold-formed steelcomposite wall applicability by using finite element analysis. Examine the validity andrationality of different analysis unit in the numerical simulation of the composite wall. Itis effectively that the connection of composite wall skeleton and wall by using linkelement combined with the technology of birth and death element;②In this paper, a series of analysis about variable parameters on shear resistanceof combined wall using cold-formed steel with no vertical load is completed. Regardingdifferent sizes of wall, the law of influence of different opening’s forms on shearresistance of combined wall is examined. The conclusions show that rate of opening isthe main factor to affect shear resistance of combined wall. With constant size of wall,shear resistance decreases in pace with increasing of opening size. And opening widthimpacts on shear resistance of combined wall more significantly;③Parametric study of shear resistance for cold-formed steel composite wall withwide open hole under the vertical load is proposed. Compared with parameters of shearresistance for composite wall under no vertical load, investigate the impact of shearresistance for composite wall under vertical load. The analysis showed that the verticalload will reduce shear capacity of composite wall with wide open hole. Its valuedecreases when the vertical load increases gradually;④For composite wall with wide open hole, current design specification does notconsider the contribution of shear resistance from the wall at the top or bottom of hole. This design idea is conservative. Refer to design specification and based on numericalsimulation results of the analysis, the formula of shear capacity for cold-formed steelcomposite wall with wide open hole from existing design specification is evaluated andcorrected.